/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.commons.exec;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Handles stream of subprocesses for {@link Executor}s.
 */
public interface ExecuteStreamHandler {

    /**
     * Sets a handler for the error stream of the subprocess.
     *
     * @param inputStream input stream to read from the error stream from the subprocess.
     * @throws IOException thrown when an I/O exception occurs.
     */
    void setProcessErrorStream(InputStream inputStream) throws IOException;

    /**
     * Sets a handler for the input stream of the subprocess.
     *
     * @param outputStream output stream to write to the standard input stream of the subprocess.
     * @throws IOException thrown when an I/O exception occurs.
     */
    void setProcessInputStream(OutputStream outputStream) throws IOException;

    /**
     * Sets a handler for the output stream of the subprocess.
     *
     * @param inputStream input stream to read from the error stream from the subprocess.
     * @throws IOException thrown when an I/O exception occurs.
     */
    void setProcessOutputStream(InputStream inputStream) throws IOException;

    /**
     * Starts handling of the streams.
     *
     * @throws IOException thrown when an I/O exception occurs.
     */
    void start() throws IOException;

    /**
     * Stops handling of the streams - will not be restarted. Will wait for pump threads to complete.
     *
     * @throws IOException thrown when an I/O exception occurs.
     */
    void stop() throws IOException;
}
